(1 ) Field of the Invention
The present invention relates to a new light-weight roofing and surfacing material and a method for the application of such material. It is particularly concerned with a surfacing material comprising a water impermeable polymeric adhesive material as a base coat for adhering sheets of synthetic polymer substrate to a suitable surface. The instant invention finds application as a roofing material for providing either an original roof or for reroofing old structures. Additionally, the present invention may also be employed as a surfacing material for any concrete or other base, and provides a particularly efficacious method for repairing damaged concrete surfaces such as sidewalks, stairs, patios and driveways.
Even more particularly, the instant invention relates to the building of a roof by covering the normal e.g. wooden base used for a roof with, if desired, tar paper or other sheet backing material, and then completely covering and sealing this layer with, for example, a urethane polymer adhesive in a flowable condition. The urethane polymer adhesive is allowed to dry or cure to a tacky condition, wide rolls of polymeric sheet material, such as synthetic polymer sheet material, are applied as a top coat, and then, if necessary, rolled to provide the necessary adherence of polymeric sheet material to the adhesive undercoat. Optionally, an electrical heating grid may be disposed within or contiguous to the polymeric adhesive.
It also relates to an exposed surfacing material for concrete surfaces, and in particular for stained, chipped, cracked, pitted, and damaged concrete surfaces. A urethane or other suitable water impermeable adhesive if applied to the damaged surface in a flowable condition. Optionally, an electric heating grid may be disposed within the adhesive membrane. The polymer adhesive is allowed to dry or cure to a tacky condition and then wide rolls of polymeric sheeting material are adhered thereto. The present invention thus provides a quick and economical method for repairing damaged concrete.
The surfacing material of the instant invention may also be employed on other surfaces wherever a water-resistant surface covering is desired, such as, for example, swimming pool decks, bathrooms, recreation rooms, kitchens, entrance ways, exterior and interior wall coverings, and other uses. Additionally by choosing polymeric materials having a high tear strength and abrasion resistance, the instant surfacing material may be employed on roads, bridges, parking lots, etc.
(2) Summary of the Prior Art
Over the span of time, numerous materials have been utilized to provide roofing materials. There are many old roofing materials, such as terracotta, slate, metals, etc., however, in the present day market, asbestos shingles, tar paper, and various other materials are used for normal roofing materials. Additionally, a significant number of relatively flat roofs are made with the use of tar and gravel, etc. Each of these normal roofing methods produces a very heavy roof, and adds to the static load which must be borne by the building structure. Significantly, the calculations which are utilized to determine the strength, and thus the size, of the beams, trusses, and other components utilized in building structures must account for the weight of the proposed roofing. Therefore, it would be of great advantage to provide a roofing material which is not only easier to repair, but is lighter weight than normal roofing materials. A significant cost saving in lumber, which is now rising rapidly in price, and other building materials, could be achieved by virtue of lightening the static load that must be borne by the support structure of a building.
Additionally, roofing materials normally come in very limited color selections, and it would be a great advantage to be able to provide customers with a large selection of colors, designs, etc., which could be marketed for new or even reroofed buildings.
Some attempts have been made to providing synthetic polymeric roofing structures. However, as can be seen, in the disclosures of U.S. Pat. Nos. 3,672,951 and 3,726,754, attempts to provide such structures have included numerous layers, significant equipments expense, and as a result do not provide the advantages of significant weight reductions. Thus these products do not result in significantly lower costs for the structure, and such reductions in cost, if available, are outweighed by increased roofing expenses. In particular, U.S. Pat. No. 3,672,951 requires at least three layers with appropriate bonding material, uses foam for insulation, a separate membrane and a second insulating layer, all the fuctions of which are incorporated in the two main layers of the present invention.
In U.S. Pat. No. 3,726,754, on the other hand, again the concept of a urethane foam is utilized, and thus more layers are required which adds weight to the overall structure. The membrane in this case is on the top and thus must be resistant to actinic light to provide longevity for the roof. The present invention, by using the adhesive as the membrane eliminates this additional component and is thus less expensive and lighter.
It is also known in the prior art to provide water resistant floor coverings. In these prior art floor coverings, the surfacing material is merely unaffected by moisture and water; it does not form a water-impermeable surface which prevents water from penetrating into the underlying concrete or wooden base. For example, U.S. Pat. No. 3,410,747, discloses an outdoor type of carpeting which comprises a mesh-type backing and a flock material secured thereto. The mesh backing is impregnated with a water resistant coating to render it resistant to mildew and to the degradative effects of water. The carpet thus does not define a water impermeable surface, but rather only a carpet resistant to the degradative effects of water. Such prior art coverings allow water to permeate onto the underlying base, resulting in mildew, rot, and cracking of the base material.
Similarly, the prior art has developed methods for repairing damages concrete. Conventionally, however, this involves applying a costly concrete or asphalt cap to the surface, or even removing and replacing the existing damaged concrete.
It is also known to provide waterproofing membranes, such as described in U.S. Pat. No. 3,900,102 by using preformed rolls of flexible sheet material such as polyethylene adhered onto a waterproof adhesive. Such preformed structures are not suitable for repairing damaged concrete or reroofing old structures which often contain large cracks or uneven areas which must be filled in with an additional material before the rolls of waterproofing material can be applied.
It would be desirable therefore to provide an economical method for repairing old roofs or damaged concrete without requiring the use of an additional filler material. Additionally, it would be desirable to provide a water impermeable, light-weight surface material suitable for use as a roofing material or as a flooring covering, particularly to lower the static load factor of building structures.